1. Field of the Invention
The present invention relates to an apparatus for receiving digital broadcasting, and more particularly, to an apparatus and a method for efficiently receiving digital broadcasting data through a channel selected by a user in a weak electric field, or other specific environments.
2. Description of the Related Art
Generally, digital broadcasting provides a user with a high-definition and high sound quality service, and significantly improves over the conventional analog broadcasting. Digital broadcasting is classified into satellite digital broadcasting and terrestrial digital broadcasting.
Satellite digital broadcasting is mainly for a mobile service and allows a user to view multi-channel multimedia broadcasting regardless of time and location through a portable receiver (e.g., a mobile phone or a personal digital assistant) or a vehicle receiver.
Terrestrial digital broadcasting, derived from digital audio broadcasting (DAB), is multimedia broadcasting received by a user in movement using an empty VHF 12 channel, and denotes transmission of complex broadcasting such as television, radio and data broadcasting using multiple channels.
Meanwhile, one channel of terrestrial digital broadcasting provides three blocks, and two video channels per one block, or one video channel and three or four audio channels per one block may be generated. In addition, terrestrial digital broadcasting aims at providing free-of-charge broadcasting to vehicles.
With the recent development of digital broadcasting and mobile communication techniques, interest has increased in a digital broadcasting service that enables a user to view digital broadcasting while the user is moving. In particular, the interest in a digital multimedia broadcasting (DMB) service through a mobile communication terminal has significantly increased.
In the meantime, if the conventional apparatus for receiving digital broadcasting (i.e., a mobile communication terminal, a vehicle receiver and a home receiver), which can be installed at a portable terminal, is located in a specific channel environment such as a weak electric field area while receiving digital broadcasting data through a channel selected by a user, the conventional apparatus for receiving digital broadcasting may not achieve the synchronization of the received digital broadcasting data. This is because the bit error rate (BER) of the received digital broadcasting data greatly increases due to characteristics of the Viterbi algorithm in the state in which the frequency of the selected channel is set.
Accordingly, the apparatus for receiving digital broadcasting unnecessarily consumes power because it continuously detects a synchronization value in order to achieve the synchronization of digital broadcasting data through the selected channel. In addition, the apparatus for receiving digital broadcasting may be down or in an inoperative state when the set frequency of the selected channel is released.